Exchange 2013 NDR Spam messages

Hi All,
I have an Exchange 2013 server configured as Mailbox Role.
The antispam solution is based on an external software (Kaspersky) that only tag emails as spam (doesn't reject emails).
I have noticed that my mail queue is full of ndr messages.

Basically, if I receive a spam email from a spoofed email address (spoofed@domain.com) to a non existing email address (xyz@mydomain.com), exchange try to send out an NDR message to the spoofed email address.
I can see that my antispam solution has marked these messages as spam (customized subject),so I want to intercept this outgoing emails to delete them.

I tried to setup a Mail Flow rule, but seems that these kind of messages are not processed by the "mail flow" module.

How can I block only these NDR messages?

Thanks